A scopolamine derivative that's been well tested.
"Monkey On His Back"
Charles V. De Vet
After Reinstrom had gone, Dr. Holmes, the attending physician of the woman whom we had seen anesthetized, missed his syringe and the bottle of scopolamine.
"The Exploits of Elaine"
Arthur B. Reeve
"Miss Sears," he asked rather testily, "what have you done with the hypodermic and the scopolamine?"
"The Exploits of Elaine"
Arthur B. Reeve